From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> This patch changes the docs and behaviour from "all states valid" to "no states valid" if no .valid callback is assigned. Users of pm_ops that only need mem sleep can assign pm_valid_only_mem without any overhead, others will require more elaborate callbacks. Now that all users of pm_ops have a .valid callback this is a safe thing to do and prevents things from getting messy again as they were before. Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Acked-by: Pavel Machek <pavel@xxxxxx> Looks-okay-to: Rafael J. Wysocki <rjw@xxxxxxx> Cc: <linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx> Cc: Greg KH <greg@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/pm.h | 12 ++++++------ kernel/power/main.c | 4 ++-- 2 files changed, 8 insertions(+), 8 deletions(-) diff -puN include/linux/pm.h~power-management-force-pm_opsvalid-callback-to-be include/linux/pm.h --- a/include/linux/pm.h~power-management-force-pm_opsvalid-callback-to-be +++ a/include/linux/pm.h @@ -125,12 +125,12 @@ typedef int __bitwise suspend_disk_metho * struct pm_ops - Callbacks for managing platform dependent suspend states. * @valid: Callback to determine whether the given state can be entered. * If %CONFIG_SOFTWARE_SUSPEND is set then %PM_SUSPEND_DISK is - * always valid and never passed to this call. - * If not assigned, all suspend states are advertised as valid - * in /sys/power/state (but can still be rejected by prepare or enter.) - * Since new states can be added for other platforms, you should - * assign this callback. There is a %pm_valid_only_mem function - * available if you only implemented mem sleep. + * always valid and never passed to this call. If not assigned, + * no suspend states are valid. + * Valid states are advertised in /sys/power/state but can still + * be rejected by prepare or enter if the conditions aren't right. + * There is a %pm_valid_only_mem function available that can be assigned + * to this if you only implement mem sleep. * * @prepare: Prepare the platform for the given suspend state. Can return a * negative error code if necessary. diff -puN kernel/power/main.c~power-management-force-pm_opsvalid-callback-to-be kernel/power/main.c --- a/kernel/power/main.c~power-management-force-pm_opsvalid-callback-to-be +++ a/kernel/power/main.c @@ -198,8 +198,8 @@ static inline int valid_state(suspend_st /* all other states need lowlevel support and need to be * valid to the lowlevel implementation, no valid callback - * implies that all are valid. */ - if (!pm_ops || (pm_ops->valid && !pm_ops->valid(state))) + * implies that none are valid. */ + if (!pm_ops || !pm_ops->valid || !pm_ops->valid(state)) return 0; return 1; } _ _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
